In recent years, imaging devices such as digital still cameras which capture images of subjects such as people, generate captured images and record these generated captured images have been spreading. Further, as such imaging devices, imaging devices which have auto-focus (AF) functions of automatically adjusting focus (focal point) upon image capturing to facilitate users' image capturing operations are widely spreading.
As such imaging devices, imaging devices which form a pair of images by pupil-dividing light having passed an image capture lens, and measure an interval between the formed images (detect a phase difference) to determine a position of the image capture lens (see, for example, Patent Document 1). This imaging device forms a pair of images by providing in an image sensor adjusted focus detection pixels which perform pupil division by blocking half of subject light received by a light reception element, and calculate an amount of misalignment of focus by measuring an interval between the formed images. Further, this imaging device adjusts focus by calculating the amount of movement of the image capture lens based on the calculated amount of misalignment of focus, and adjusting the position of the image capture lens based on the calculated amount of movement (focus adjustment).